The senior US prosecutor investigating links between Prince Andrew and Jeffrey Epstein has vowed to carry on with his enquiries despite a dramatic attempt by the Trump administration to force him to resign. In a late-night announcement on Friday, US attorney general William Barr declared Geoffrey Berman was stepping down, a development seen by critics as designed to benefit Trump politically and challenge the independence of the Justice Department. But it also comes at a delicate time in the inquiry led by Berman, the US attorney in Manhattan, into Prince Andrew’s links to convicted sex offender Epstein. Berman and the Duke of York have become embroiled in a series of public rows over what the US prosecutor alleges is his refusal to answer questions in their investigation into allegations of sex trafficking and other crimes against Epstein. Earlier this month the prince’s lawyers struck back, saying in a statement from London that he had agreed three times to help New York prosecutors. Despite Berman’s abrupt attempted dismissal it appears that his inquiry will not be derailed. Within two hours of learning that the Trump administration wanted him out, Berman moved to reassure that he would continue the investigations, which also include one into US president Donald Trump’s personal lawyer. Explaining that he had learned of his apparent resignation from the nation’s most prominent federal prosecutor’s office through a press release issued by Barr, Berman said he had “no intention of resigning my position”. He added: “I will step down when a presidentially appointed nominee is confirmed by the Senate. Until then, our investigations will move forward without delay or interruption.” Although Barr offered no reason for why he had announced that Berman was stepping down, its timing was interpreted as an another attempt by Trump to purge officials perceived as not being sufficiently loyal. In recent weeks he has fired a series of agency watchdogs, including one who played a key role in Trump’s impeachment. Appointed in January 2018, Berman has not shied away from investigating some of Trump’s closest allies. His office oversaw the prosecution of Michael Cohen, Trump’s former personal lawyer, who has served a prison sentence for lying to Congress and for election campaign finance fraud. Berman’s office has also been investigating the conduct of Rudy Giuliani, Trump’s current personal lawyer, though prosecutors have not accused Giuliani of wrongdoing. The latest development prompted senior Democrats to accuse Barr of politicising the justice department and making legal decisions on behalf of Trump. The row comes days after former national security adviser John Bolton revealed in a book allegations that Trump attempted to interfere with a probe overseen by Berman’s office. There is no sign that Berman will respond to what appear to be the latest intentions of the US president. “I cherish every day that I work with the men and women of this office to pursue justice without fear or favour - and intend to ensure that this office’s important cases continue unimpeded,” he said. Prince Andrew has faced severe scrutiny over his friendship with Epstein, but has repeatedly said that he never witnessed any suspicious behaviour during visits to the financier’s home and has always denied any wrongdoing. Shortly after a heavily criticised BBC interview at the end of last year about the duke’s relationship with Epstein was broadcast, Prince Andrew said he was “willing to help any appropriate law enforcement agency” with their investigations. However, at the start of the year Berman announced that the prince had provided “zero co-operation”, and in March added that Andrew had “completely shut the door” on helping investigators. The duke stepped away from royal duties following the BBC interview. Epstein took his own life in a US jail cell last August, aged 66, while awaiting trial.